This invention relates to an end-trimming apparatus for finishing into flat faces both ends of a roll products comprising a sheet material wound up on a core, particularly, stretchable one such as plastics film, by cutting off the irregularity of both the roll ends.
It is very difficult to wind up sheet materials such as plastics film, paper, and metal foil, which are continuously delivered, on hollow cores into rolls with flat ends, and even the use of a device for preventing the meandering running of the sheet cannot attain perfection. This trend will be more apparent as the running speed of the sheet increases and, particularly when the sheet is a stretchable one such as plastics film, it is further enhanced by the additional effect of tension exerted on the film, thus resulting in the irregular ends of the roll, as shown in magnification in FIG. 1. This irregularity of the roll ends not only decreases the commercial value of the products, but also causes troubles such that the sheet is often teared during the operation by extreme partial tensions exerted on the folded portions S2 of the sheet, which are protrusions of the sheet sides folded underneath the adjacent portions S1 of the sheet. This will lead to an increase in rejected products in the packing process due to broken sheets.